Sear-mechanism for firearms



Feb. 9, 1937. A F LAUDENSACK 2,069,887

SEAR MECHANISM FOR FIREARMS Filed July 51, `1955 4 SheecS-SheeiI l Feb- 9, 1937- A. F, LAUDENSAGK 2,059,887

SEAR MECHANISM FOR FIREARMS Filed July 3l, 1935 4 Sheets-Sheet 2 y Feb. 9, 1937. A. F. LAuDENsAcK 2,069,887

SEAR MECHANISM FOR FIREARMS Filed July 3l, 1935 4 Sheets-Sheet 5 Feb. 9, 1937. A. F. LAUDENSACK 2,069,887

SEAR MECHANISM FOR FIREARMS Filed July 3l, 1935 4 Sheets-Sheet 4 Lw ma;

l illu.

Patented Feb. 9, 1937 PATENT OFFICE SEAR-MECHANISM FOR FIREARMS Albert F. Laudensack, New Haven, Conn., assignor to Winchester Repeating Arms Company, New Haven, Maryland Conn., a corporation of Application July 31, 1935. Serial No. 33,957

16 Claims.

This invention relates to an improvement in rearrns and relates in particular to Sear-mechnisms therefor.

One of the objects of the present invention is 3 provide a Sear-mechanism for firearms which i characterized by superior reliability.

Another object is to provide a superior seariechanism especially adapted for up-turn-andullback bolt-action firearms.

A. further object is to produce a superior seariechanism for firearms which will provide for a .lbstantially-uniform trigger-pull.

A still further object is to provide a bolt-action rearm in which uniformity of trigger-pull is ssured, despite variations in the speed at which 1e bolt thereof is closed.

With the above and other objects in view, as 'ill `appear to those skilled in the art from the illowing, considered in conjunction with the ac- )mpanying drawings and appended claims, the resent invention includes all features disclosed ierein which are novel over the prior art.

In the accompanying drawings:

Fig. 1 is a broken view in side elevation of an pturn-and-pullback bolt-action firearm emodying the present invention, with the stock and ssociated parts omitted;

Fig. 2 is an: under-side View thereof;

Fig. 3 is a `vertical central-longitudinal seconal view thereof, with the parts shown in the ositions which they assume when the rearm is ncked; i Y

Fig. .4 is a 'transverse sectional view taken on ie line 4 4 of Fig.'3; v

Fig. 5 is-a view similar to Fig. 3, but showing 1e parts inthe positions which they assume nmediately after the firearm is fired;

Fig. 6 is a similar iview. but showing the parts i the positions which they assume after the firerm has been fired and theubolt-operating handle as been upturned, preparatory to the retraction i the bolt; l

Fig. 'l is a-transverse sectional View taken on ie line I--l ofaFig. 6;

Fig. 8 is a perspective View of the scar; and

Fig. 9 is a perspective view'of the bolt-op- .'ating handle.

The particular firearm herein chosen for the lustration of the present invention is of the i-called "upturn-and-pullback bolt-action therein. The receiver is also provided with an axial bolt-receiving passage 2`4, the forward upper portion of which is intersected by a loading-and-ejection opening 25.

Mounted in the bolt-receiving passage 24 of the 5 receiver 20, with capacity for reciprocation therein, is a cylindrical bolt 26 having an axial firing-pin passage 21 therein intersected at its forward end by a relatively-small eccentric passage 28. Projectable through the said passage 1o 28 is the firing-point 29 of a firing-plunger 30 mounted in the passage 21 in the bolt 26.

The rear portion of the firing-plunger 30 is of tubular form in cross-section and provides a ring-spring chamber 3| receiving a firing-spring 15 32, which latter thrusts at its forward end against the front wall 33 of the firing-spring chamber 3l. The rear end of the firing-spring 32 is seated against a pin 34 mounted in and extending transversely through the reduced cylindrical rear por- 20 tion 35 of the bolt 26. 'Ihe said pin extends through longitudinal clearance-slots 36-36 respectively formed in the rear portion of the top and bottom walls of the firing-plunger 30 so that the said firing-plunger may reciprocate inde- 25 pendently of the bolt 2E but, at the same time, be prevented from relative rotary movement with respect thereto.

As shown, the rear end of the ring-plunger 3U may be provided with a head 31 having forwardlyo extending nibs 38-38 adapted to enter complementary notches 39-39 in the rear edge of a bolt-operating sleeve 40 which is mounted with capacity for turning movement upon the reduced cylindrical rear portion 35 of the bolt 26 and pro- 35 vided with an integral laterally-offsetting handle 4I terminating in a ball-grip 42.

Intermediate its respective opposite ends, the under-portion of the firing-plunger 30 is transversely cut away to provifie a substantially-verti- 40 cal forwardly-facing cooking-shoulder 43 adapted to be engaged, when the firearm is cocked, by the rear face 44 of a scar-nose 45 vertically upstanding from a pivotal sear 46. The said sear is pivotally mounted adjacent its forward end by means 45 of a transverse pivot-pin` 41, in a vertically-extending passage 48 formed in the under side of the receiver 20. 'I'he said Sear-nose 45 of the sear 46 projects upwardly for the engagement of its rear face 44 with the cooking-shoulder 43, 50 through a longitudinal clearance-slot 49 formed in the under side of the bolt 26.

The portion of the sear 46 which is located forwardly of the pin 41 is provided with an upwardlyopening spring-pocket 50 receiving a Sear-spring 55 55 pending from a trigger-bracket 16.

an upwardly-facing Sear-engaging shoulder 56 formed upon the trigger 54 before referred to.

To limit the degree of overlap of the triggerengaging shoulder 55 and the scar-engaging shoulder 56, the upper portion of the said trigger l5 54 is provided with an inclined adjusting-screw 51, the rear terminal of which is engageable with the rear wall 58 of the passage 52 in the sear 46 for the purpose just referred to.

The rear portion of the sear 46 is formed with an upwardly-opening pocket 59 receiving a searactuating plunger 66 having a stern 6I downwardly-extending through a bearing-passage 62 opening downwardly through the sear 46 from the lower end of the said pocket 59 therein. The

stem 6i of the scar-actuating plunger 66 is encircled by a scar-actuating spring 63 housed in the pocket 59 of the sear 46 and exerting a constant e'ort to move the plunger 66 upwardly with respect to the sear 46, and hence tending, under certain conditions as will hereinafter appear, to

depress the rear end of the said sear.

'I'he upper terminal of the Sear-actuating plunger 66 is adapted to engage, when the bolt 26 is in its closed position, with a detent-notch 64 formed in the` bolt-operating sleeve 46 before referred to, as shown in Figs. 3 and 4 of the drawings. The upper end of the said plunger 66 is also adapted, when the bolt-operating handle is in its elevated position, as indicated in Figs. 6

40 and 7, to engage with a cam-surface 65 also formed upon the exterior surface of the boltoperating sleeve 46. Under the conditions just described, the upward movement olf the Sear-actuating plunger 66 with respect to the scar 46 is limited. by a stop-pin 66- extending transversely through the stem 6I of the said plunger and engageable for the purpose described with the under face of the adjacent portion of the sear 46, as illustrated in Fig.' 6.

'I'he trigger 54 before described is pivoted intermediate its upper end 53 and itsnger-piece 61 by means of a pivot-pin 66 extending transversely thereof and mounted at its respective opposite ends in complementary ngers 69-69 de- The said trigger-bracket is of substantially U-shaped form in horizontal section, as indicated in Fig. 2, and has its respective opposite side walls 1 |-1 I, from which the ingers6969 depend, attached to the receiver 26 by means of the pin 41 upon which the sear 46 swings.

The rear wall 12 of the trigger-bracket 16 is bent to provide two rearwardly-extending ears 13 and 14. The ear 13 just referred to has extending through it a s'crew 15 threaded into the under wall of the receiver 26 and serving to secure the rear end of thesaid ytrigger-bracket in place. The ear 14 justV referred to oi' the triggerbracket 16 mounts an internally-threaded bushing 16 receiving an adjusting-screw .11, the lower end of which engages the upper end of a triggerspring 18, which latter has its lower end seated in a pocket 19 formed in the upper rear face of '-the finger-piece 61 of the trigger 54.

For the purpose of a better understanding 0f the operation of the mechanism above described let it be presumed that the parts are in the positions in which they are indicated in Fig. 3. Ir the figure referred to, it will be noted that th( breech-bolt is in its fully-closed-and-locked position and that the upper end of the Sear-actuating plunger 60 is entered into the detent-notch 64 i1 the bolt-operating sleeve 46, thereby placing th( Sear-actuating spring 63 under tension whicl tends to depress the rear end of the sear 46. Th( depression of the rear end of the said sear i: prevented at this time, however, by the resting of the trigger-engaging shoulder 55 of the saic sear upon the Sear-engaging shoulder 56 of the trigger 54.

If, now, the trigger 54 be operated by means o1 its finger-piece 61 to move its Sear-engaging shoulder 56 forwardly from under the trigger engaging shoulder 55 of the sear 46, the searactuating springs 63 will assert itself and swing the rear end of the said sear downwardly tc withdraw the sear-nose 45' of the latter out oi the path of the cooking-shoulder 43 of the firingplunger 36. The said firing-plunger will thus bs permitted to snap forwardly under the urge o1 its firing-spring 32 to impinge its firing-point 2l against the rim of a cartridge located in the cartridge-chamber 23 of the barrel 22.

The movement of the seal 46 above describec' is effected by the scar-actuating spring 63 agains the resistance of the scar-spring 5|, owing to the location of the former spring at a greater distance from the transverse pin 41 than is the latte] spring 5I. It may be noted that when the searactuated spring 63 acts to downwardly swing the rear end of the sear 46, as above described, there will be very slight retraction of the firing-pir until such time as the upper rear corner of the Sear-nose 45 clears the lower forward corner oi the cooking-shoulder 43 of the said firing-pin.

The parts will now have assumed the position: in which they are indicated in Fig. 5.

'Ihe firearm having been fired, the next norma. step in the use thereof would be to swing the bolt-handle 4| upwardly from the position 1r which it is shown in Fig. 4 into the position ir which it is shown in Fig. '1, thereby turning the bolt-operating sleeve 46 into position to bring it: cam-surface 65 into registration with the uppei end of the scar-actuating plunger 66, thus permitting the said plunger to move upwardly witl: reference to the sear 46 under the urge of the scar-actuating spring 63 until the stop-pin 66 o1 the said plunger engages the under face of the adjacent portion of the sear 46.

'I'he engagement of the stop-pin `66 with the sear 46 as just above described serves to relieve the rear end of the said sear from any furthe] downward urge by the spring 63 and, owing tc the clearance provided by the cam-surface 65 and the clearance-slot 49 in the bolt 26, the triggerengaging shoulder of the said sear will be permitted to be raised by the Sear-spring 5I to a point slightly above the scar-engaging shouldel 56 of the trigger 54, whereupon the said trlggel will swing in a counterclockwise direction a: viewed in the drawings, to again interpose it: shoulder 56 in the path of downward movemen of the shoulder 55 of the sear 46.

The parts will now have assumed the position: in which they are shown in Fig. 6.

The bolt 26 may now be moved axially rearwardly by its now-upturned handle 4I to effect the extraction and ejection of the fired cartridge iAfter the bolt 26 has been moved to the limit o1 VY"rg-ear 45 Slightly downwardly until such movement its normal rearward travel, it may then be moved forwardly by means of its handle 4I to engage the cooking-shoulder 43 of the firing-plunger 30 with the rear face 44 of the sear-nose 45. 'I'he further forward travel of the bolt will compress the firing-spring 32 and ultimately bring the cam-surface 65 of the bolt-operating sleeve 40 into position for engagement with the upper end of the sear-actuating plunger 60.

Now when the handle 4| of the bolt-operating sleeve 40 is swung downwardly into its normal position, in which its rear surface engages with a locking-abutment 80 in the side wall of the receiver 20, the cam-surface 65 of the said bolt-operating sleeve 40 will act to fully depress the searactuating plunger 60, thus tensioning the searactuating spring 63. The said spring 63 will, when so tensioned, swing the rear portion of the is checked by the engagement of the shoulder 55 of the said sear with the shoulder 56 of the trigger 54.

The parts will now have reassumed the positions in which they are shown in Fig. 3, in which gure, it will be observed, the sear-engaging shoulder 56 of the trigger 54 extends rearwardly beneath the trigger-engaging shoulder 55 of the sear 46 and thus prevents the sear-actuating spring 63 from depressing the rear portion of the said sear until such time as the .trigger is again pulled.`

By means of the foregoing construction, a rearm is provided in which the trigger-pull required to eect the release of the tiring-plunger 30, or other firing-member, is markedly uniform, thus providing a rearm having, to an outstanding degree, one of the qualities most desired by marksmen.

lmember in its cocked position; a trigger having a portion coacting with the said sear to releasably hold the same in position to restrain the said firing-member; and spring-means urging the said sear into its ring-member-releasing position when the firearm is cocked, and also serving to move the said sear into position to release the said firing-member when the said trigger is operated.

2. A sear-mechanism for firearms, including in combination: a spring-pressed firing-member; a sear serving to releasably hold the said firingmember in its cocked position; a trigger having a portion coacting with the said sear to releasably hold the same in position to restrain the said riring-rnember; spring-means urging the said sear into a. position to hold the said firing-member in its cocked position; and second spring-means urging the said sear into its lring-member-releasing position when the firearm is cocked, and also serving to move the said sear into position to release the said firing-member when the said trigger is operated.

3. A sear-mechanism for firearms, including in combination: a spring-pressed ring-member; a

sear serving to releasably hold the said ringmember in its cocked position; a trigger having a portion coacting with the said sear to releasably hold the same in position to restrain the said nringmember; and spring-means carried by the said sear and urging the said sear into its ringmember-releasing position when the firearm is cocked, and also serving to move the same into position to release the said firing-member when the said trigger is operated.

4. A sear-mechanism for rearms, including in combination: a spring-pressed firing-member; a sear serving to releasably hold the said ringmember in its cocked position; a trigger having a portion coacting with the said sear to releasably hold the same in position to restrain the said firing-member; spring-means urging the said sear into a position to hold thersaid firing-member innr its cocked position; and second spring-means carried by the said sear and urging the said sear into its tiring-member-releasing position when the rearm is cocked, and also serving to move the same into position to release the said firingmember when the said trigger is operated.

5. A sear-mechanism for firearms, including in combination: a spring-pressed firing-member; a sear serving to releasably hold the said firingmember in its cocked pcsition; a trigger having a portion coacting with the said sear to releasably hold the same in position to restrain the said firing-member; and a spring-pressed plunger urging the said sear into its firing-member-releasing position when the firearm is cocked, and also serving to move the said sear into position to release the said firing-member when the said trigger is operated.

6. A sear-mechanism for firearms, including in combination: a spring-pressed firing-member; a sear serving to releasably hold the said firingmember in its cocked position; a trigger having a portion coacting with the Said sear to releasably hold the same in position to restrain the said fring-member; spring-means urging the said sear into a position to hold the said firing-member in its cocked position; and a spring-pressed plunger carried by the said sear and urging the said sear into its tiring-member-releasing position when the firearm is cocked, and also serving to move the same into position to release the said firingmember when the said trigger is operated.

7. In a bolt-action firearm, the combination with the bolt-unit thereof, of a spring-pressed ring-member; a sear serving to releasably hold the said ring-member in its cocked position; a trigger controlling the said sear; spring-means urging the said sear into position to hold the said ring-member in its cocked position; and second spring-means constructed and arranged to be tensioned and relaxed by the movement of the lsaid bolt-unit and serving when tensioned to sioned by the closing movement of the said boltunit and relaxed by the opening movement thereof and serving when so tensioned to move the said sear into position to release the said ring-member when the said trigger is operated.

9. In a bolt-action rearm, the combination with the bolt-unit thereof, of a spring-pressed firing-member; a sear serving to releasably hold the said firing-member in its cocked position; a trigger controlling the said sear; spring-means urging the. said sear in a position to hold the said firing-member in its cocked position; and second spring-means carried by the said sear and constructed and arranged to be tensioned to move the said sear into position to release the said ring-member when the said trigger is operated.

10. In abou-action firearm, the combination with the bolt-unit thereof, of a spring-pressed tiring-member; a sear serving to releasably hold the said tiring-member in its cocked position; a trigger controlling the said sear; spring-means urging the said sear in a position to hold the said ring-member in its cocked position; and second spring-means carried by the said sear and constructed and arranged to be tensioned by the closingV movement of the said bolt-unit and relaxed by the opening movement thereof and serving when so tensioned to move the said sear into position to release the said tiring-member when the said trigger is operated.

11. In a bolt-action firearm, the combination with the bolt-unit thereof, or a spring-pressed firing-member; a sear serving to releasably hold the said tiring-member in its cocked position; a trigger controlling the said sear; spring-means urging the said sear in a position to hold the said firing-member in its cocked position; and a spring-pressed plunger carried by the said sear and constructed and arranged to be tensioned and relaxed by the movement of the bolt-unit and serving when tensioned to move the said sear into position to release the said ring-member when the said trigger is operated.

12. In an upturn-and-pullback firearm, the combination with a bolt-unit including a bolthandle swinging transversely of the rearm; of a spring-pressed firing-member; a sear serving to releasably hold the said firing-member in its cocked position; a trigger coacting with the said sear; spring-means urging the said sear into position to hold the said ring-member in its cocked position; and second spring-means constructed and arranged to be tensioned and relaxed by the swinging movement of the said bolt-handle and serving when tensioned to move the said sear into position to release the said firing-member when the said trigger is operated.

13. In an upturn-and-pullback firearm, the combination with a bolt-unit including a bolthandle swinging transversely of the rearm; of a spring-pressed firing-member; a sear serving to releasably hold the said tiring-member in its cocked position; a trigger coacting with the said sear; spring-means urging the said sear into position to hold the said ring-member in its cocked position; and second spring-means constructed and arranged to be tensioned by the bolt-locking movement of the said bolt-handle and relaxed by the unlocking movement thereof and serving when so tensioned to move the said sear into position to release the said firing-member when the said trigger is operated.

14. In an upturn-and-pullback firearm, the combination with a bolt-unit including a bolthandle swinging transversely of the rearm; of a spring-pressed firing-member; a sear serving to releasably hold the said firing-member in its cocked position; a trigger coacting with the said sear; spring-means urging the said sear in a position to hold the said ring-member in its cocked position; and second spring-means carried by the said seal` and constructed and arranged to be tensioned and relaxed by the swinging movement of the said bolt-handle and serving when tensioned to move the said sear into position to release the said firing-member when the said trigger is operated.

15. In an upturn-and-pullback firearm, the combination with a bolt-unit including a bolthandle swinging transversely of the rearm; of a spring-pressed firing-member; a sear serving to releasably hold the said firing-member in its cocked position; a trigger coacting with the said seat; spring-means urging the said sear in a position to hold the said tiring-member in its cocked position; and second spring-means carried by the said sear and constructed and arranged to be tensioned by the bolt-locking movement of the said bolt-handle and relaxed by the unlocking movement thereof and serving when so tensioned to move the said sear into position to release the said firing-member when the said trigger is operated.

16. In an upturn-and-pullback firearm, the combination with a bolt-unit including a bolthandle swinging transversely of the arm; of a spring-pressed tiring-member; a sear serving to releasably hold the said firing-member in its cocked position; a trigger coacting with the said sear; spring-means urging the said sear in a position to hold the said ring-member in its cocked position; and a spring-pressed plunger carried by the said scar and constructed and arranged to be tensioned and relaxed by the swinging movement of the said bolt-handle and serving when'tensioned to move the said sear into position to re- ,t

lease the said rlng-member when the said trigger is operated.

ALBERT F. LAUDENSACK.

D llsoLAi M E R '2,069,887.Albe1t F. Laudensaek, New Haven, Conn. SEAR-MECHANISM FOR FIRE- ARMS.

Patent dated February 9, 1937. Disclaimer filed September 2,

1938, by the patentee; the assignee, Winchester Repeating Arms Company,

concurring. Hereb disclaims claims l, 2, 5, and 7.

[ etal Gazette September 27, 1.938.] 

